Here, \(d\)  and \(b\)  are the distance and Galactic latitude of a star, respectively, and \(H\)  indicates the scaleheight of the Galactic dust [1]}. Distances of the stars are calculated by using the trigonometric parallaxes in Gaia DR2 via the equation \(d{\rm (pc)}=1000/\pi \) (mas). The median distances of the main-sequence, sub-giant and giant stars are 33, 49 and 83 pc, respectively. Thus, the colour excesses \(E_d(B-V)\)  and \(E_d(U-B)\)  could be calculated by replacing the total absorption \(A_d(b)\)  in the following equations of [2]} and [3]}:

\(E_d(B-V)=A_d(b)/3.1\\ \nonumber E_d(U-B)=0.72\times E_d(B-V)+0.05\times E_d(B-V)^2\) 
